Attachment #228412 for bug #256937




 */
void
fuse_internal_cache_attrs(struct vnode *vp, struct fuse_attr *attr,
	uint64_t attr_valid, uint32_t attr_valid_nsec, struct vattr *vap,
	bool from_server)
{
	struct mount *mp;
	struct fuse_vnode_data *fvdat;

	fuse_validity_2_bintime(attr_valid, attr_valid_nsec,
		&fvdat->attr_cache_timeout);

	if (vnode_isreg(vp) &&
	    fvdat->cached_attrs.va_size != VNOVAL &&
	    attr->size != fvdat->cached_attrs.va_size)
	{
		if ( data->cache_mode == FUSE_CACHE_WB &&
		    fvdat->flag & FN_SIZECHANGE)
		{
			const char *msg;

			/*
			 * The server changed the file's size even though we're
			 * using writeback cacheing and and we have outstanding
			 * dirty writes!  That's a server bug.
			 */
			if (fuse_libabi_geq(data, 7, 23)) {
				msg = "writeback cache incoherent!."
				    "To prevent data corruption, disable "
				    "the writeback cache according to your "
				    "FUSE server's documentation.";
			} else {
				msg = "writeback cache incoherent!."
				    "To prevent data corruption, disable "
				    "the writeback cache by setting "
				    "vfs.fusefs.data_cache_mode to 0 or 1.";
			}
			fuse_warn(data, FSESS_WARN_WB_CACHE_INCOHERENT, msg);
		}
		if (fuse_vnode_attr_cache_valid(vp) &&
		    data->cache_mode != FUSE_CACHE_UC)
		{
			/*
			 * The server changed the file's size even though we
			 * have it cached and our cache has not yet expired.
			 * That's a bug.
			 */
			fuse_warn(data, FSESS_WARN_CACHE_INCOHERENT,
			    "cache incoherent!  "
			    "To prevent "
			    "data corruption, disable the data cache "
			    "by mounting with -o direct_io, or as "
			    "directed otherwise by your FUSE server's "
			    "documentation.");
		}
	}

	/* Fix our buffers if the filesize changed without us knowing */
	if (vnode_isreg(vp) && attr->size != fvdat->cached_attrs.va_size) {
		(void)fuse_vnode_setsize(vp, attr->size, from_server);
		fvdat->cached_attrs.va_size = attr->size;
	}


	fuse_vnode_clear_attr_cache(dvp);

	fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,
		feo->attr_valid_nsec, NULL, true);

	return err;
}

		fao->attr.mtime = old_mtime.tv_sec;
		fao->attr.mtimensec = old_mtime.tv_nsec;
	}
	if (vnode_isreg(vp) &&
	    fvdat->cached_attrs.va_size != VNOVAL &&
	    fao->attr.size != fvdat->cached_attrs.va_size) {
		/*
		 * The server changed the file's size even though we had it
		 * cached!  That's a server bug.
		 */
		struct mount *mp = vnode_mount(vp);
		struct fuse_data *data = fuse_get_mpdata(mp);

		fuse_warn(data, FSESS_WARN_CACHE_INCOHERENT,
		    "cache incoherent!  "
		    "To prevent data corruption, disable the data cache "
		    "by mounting with -o direct_io, or as directed "
		    "otherwise by your FUSE server's documentation.");
		int iosize = fuse_iosize(vp);
		v_inval_buf_range(vp, 0, INT64_MAX, iosize);
	}
	fuse_internal_cache_attrs(vp, &fao->attr, fao->attr_valid,
		fao->attr_valid_nsec, vap, true);
	if (vtyp != vnode_vtype(vp)) {
		fuse_internal_vnode_disappear(vp);
		err = ENOENT;

		struct fuse_attr_out *fao = (struct fuse_attr_out*)fdi.answ;
		fuse_vnode_undirty_cached_timestamps(vp);
		fuse_internal_cache_attrs(vp, &fao->attr, fao->attr_valid,
			fao->attr_valid_nsec, NULL, false);
	}

out:

Lines 223-229 int fuse_internal_access(struct vnode *vp, accmode_t mode, Link Here

(-)b/sys/fs/fuse/fuse_internal.h (-1 / +2 lines)
223		223
224	/* attributes */	224	/* attributes */
225	void fuse_internal_cache_attrs(struct vnode vp, struct fuse_attr attr,	225	void fuse_internal_cache_attrs(struct vnode vp, struct fuse_attr attr,
226	uint64_t attr_valid, uint32_t attr_valid_nsec, struct vattr *vap);	226	uint64_t attr_valid, uint32_t attr_valid_nsec, struct vattr *vap,
		227	bool from_server);
227		228
228	/* fsync */	229	/* fsync */
229		230




		as_written_offset = uio->uio_offset - diff;

		if (as_written_offset - diff > filesize)
			fuse_vnode_setsize(vp, as_written_offset, false);
		if (as_written_offset - diff >= filesize)
			fvdat->flag &= ~FN_SIZECHANGE;


			 * Extend file _after_ locking buffer so we won't race
			 * with other readers
			 */
			err = fuse_vnode_setsize(vp, uio->uio_offset + n, false);
			filesize = uio->uio_offset + n;
			fvdat->flag |= FN_SIZECHANGE;
			if (err) {

		/*
	         * Setup for actual write
	         */
		/*
		 * If the file's size is cached, use that value, even if the
		 * cache is expired.  At this point we're already committed to
		 * writing something.  If the FUSE server has changed the
		 * file's size behind our back, it's too late for us to do
		 * anything about it.  In particular, we can't invalidate any
		 * part of the file's buffers because VOP_STRATEGY is called
		 * with them already locked.
		 */
		filesize = fvdat->cached_attrs.va_size;
		/* filesize must've been cached by fuse_vnop_open.  */
		KASSERT(filesize != VNOVAL, ("filesize should've been cached"));

		if ((off_t)bp->b_lblkno * biosize + bp->b_dirtyend > filesize)
			bp->b_dirtyend = filesize - 

Lines 389-399 fuse_vnode_savesize(struct vnode vp, struct ucred cred, pid_t pid) Link Here

(-)b/sys/fs/fuse/fuse_node.c (-3 / +16 lines)
389	}	389	}
390		390
391	/*	391	/*
392	* Adjust the vnode's size to a new value, such as that provided by	392	* Adjust the vnode's size to a new value.
393	* FUSE_GETATTR.	393	*
		394	* If the new value came from the server, such as from a FUSE_GETATTR
		395	* operation, set `from_server` true. But if it came from a local operation,
		396	* such as write(2) or truncate(2), set `from_server` false.
394	*/	397	*/
395	int	398	int
396	fuse_vnode_setsize(struct vnode *vp, off_t newsize)	399	fuse_vnode_setsize(struct vnode *vp, off_t newsize, bool from_server)
397	{	400	{
398	struct fuse_vnode_data *fvdat = VTOFUD(vp);	401	struct fuse_vnode_data *fvdat = VTOFUD(vp);
399	struct vattr *attrs;	402	struct vattr *attrs;
Lines 434-439 fuse_vnode_setsize(struct vnode *vp, off_t newsize) Link Here
434	MPASS(bp->b_flags & B_VMIO);	437	MPASS(bp->b_flags & B_VMIO);
435	vfs_bio_clrbuf(bp);	438	vfs_bio_clrbuf(bp);
436	bp->b_dirtyend = MIN(bp->b_dirtyend, newsize - lbn * iosize);	439	bp->b_dirtyend = MIN(bp->b_dirtyend, newsize - lbn * iosize);
		440	} else if (from_server && newsize > oldsize && oldsize != VNOVAL) {
		441	/*
		442	* The FUSE server changed the file size behind our back. We
		443	* should invalidate the entire cache.
		444	*/
		445	daddr_t left_lbn, end_lbn;
		446
		447	left_lbn = oldsize / iosize;
		448	end_lbn = howmany(newsize, iosize);
		449	v_inval_buf_range(vp, 0, end_lbn, iosize);
437	}	450	}
438	out:	451	out:
439	if (bp)	452	if (bp)

Lines 201-207 void fuse_vnode_open(struct vnode *vp, int32_t fuse_open_flags, Link Here

(-)b/sys/fs/fuse/fuse_node.h (-1 / +1 lines)
201		201
202	int fuse_vnode_savesize(struct vnode vp, struct ucred cred, pid_t pid);	202	int fuse_vnode_savesize(struct vnode vp, struct ucred cred, pid_t pid);
203		203
204	int fuse_vnode_setsize(struct vnode *vp, off_t newsize);	204	int fuse_vnode_setsize(struct vnode *vp, off_t newsize, bool from_server);
205		205
206	void fuse_vnode_undirty_cached_timestamps(struct vnode *vp);	206	void fuse_vnode_undirty_cached_timestamps(struct vnode *vp);
207		207




	struct fuse_entry_out *feo;
	struct fuse_vnode_data *fvdat;
	const char dot[] = ".";
	off_t filesize;
	enum vtype vtyp;
	int error;


	error = fuse_vnode_get(mp, feo, nodeid, NULL, vpp, NULL, vtyp);
	if (error)
		goto out;
	filesize = feo->attr.size;

	/*
	 * In the case where we are looking up a FUSE node represented by an
	 * existing cached vnode, and the true size reported by FUSE_LOOKUP
	 * doesn't match the vnode's cached size, then any cached writes beyond
	 * the file's current size are lost.
	 *
	 * We can get here:
	 * * following attribute cache expiration, or
	 * * due a bug in the daemon, or
	 */
	fvdat = VTOFUD(*vpp);
	if (vnode_isreg(*vpp) &&
	    filesize != fvdat->cached_attrs.va_size &&
	    fvdat->flag & FN_SIZECHANGE) {
		if (data->cache_mode == fuse_data_cache_mode) {
			const char *msg;

			if (fuse_libabi_geq(data, 7, 23)) {
				msg = "writeback cache incoherent!."
				    "To prevent data corruption, disable "
				    "the writeback cache according to your "
				    "FUSE server's documentation.";
			} else {
				msg = "writeback cache incoherent!."
				    "To prevent data corruption, disable "
				    "the writeback cache by setting "
				    "vfs.fusefs.data_cache_mode to 0 or 1.";
			}
			fuse_warn(data, FSESS_WARN_WB_CACHE_INCOHERENT, msg);
		} else {
			/* If we get here, it's likely a fusefs kernel bug */
			printf("%s: WB cache incoherent on %s!\n", __func__,
			    vnode_mount(*vpp)->mnt_stat.f_mntonname);
		}
		fvdat->flag &= ~FN_SIZECHANGE;
	}

	fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,
		feo->attr_valid_nsec, NULL, true);
	fuse_validity_2_bintime(feo->entry_valid, feo->entry_valid_nsec,
		&fvdat->entry_cache_timeout);
out:




	struct fuse_bmap_in *fbi;
	struct fuse_bmap_out *fbo;
	struct fuse_data *data;
	struct fuse_vnode_data *fvdat = VTOFUD(vp);
	uint64_t biosize;
	off_t fsize;
	daddr_t lbn = ap->a_bn;
	daddr_t *pbn = ap->a_bnp;
	int *runp = ap->a_runp;

	 */
	if (runb != NULL)
		*runb = MIN(lbn, maxrun);
	if (runp != NULL && maxrun == 0)
		*runp = 0;
	else if (runp != NULL) {
		/*
		 * If the file's size is cached, use that value to calculate
		 * runp, even if the cache is expired.  runp is only advisory,
		 * and the risk of getting it wrong is not worth the cost of
		 * another upcall.
		 */
		if (fvdat->cached_attrs.va_size != VNOVAL)
			fsize = fvdat->cached_attrs.va_size;
		else
			error = fuse_vnode_size(vp, &fsize, td->td_ucred, td);
		if (error == 0)
			*runp = MIN(MAX(0, fsize / (off_t)biosize - lbn - 1),
				    maxrun);
		else
			*runp = 0;

	}
	ASSERT_VOP_ELOCKED(*vpp, "fuse_vnop_create");
	fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,
		feo->attr_valid_nsec, NULL, true);

	fuse_filehandle_init(*vpp, FUFH_RDWR, NULL, td, cred, foo);
	fuse_vnode_open(*vpp, foo->open_flags, td);

		 */
		fuse_vnode_clear_attr_cache(tdvp);
		fuse_internal_cache_attrs(vp, &feo->attr, feo->attr_valid,
			feo->attr_valid_nsec, NULL, true);
	}
out:
	fdisp_destroy(&fdi);

			*vpp = dvp;
		} else {
			struct fuse_vnode_data *fvdat;
			struct vattr *vap;

			err = fuse_vnode_get(vnode_mount(dvp), feo, nid, dvp,
			    &vp, cnp, vtyp);
			if (err)
				goto out;
			*vpp = vp;

			/*
			 * In the case where we are looking up a FUSE node
			 * represented by an existing cached vnode, and the
			 * true size reported by FUSE_LOOKUP doesn't match
			 * the vnode's cached size, then any cached writes
			 * beyond the file's current size are lost.
			 *
			 * We can get here:
			 * * following attribute cache expiration, or
			 * * due a bug in the daemon, or
			 */
			fvdat = VTOFUD(vp);
			if (vnode_isreg(vp) &&
			    ((filesize != fvdat->cached_attrs.va_size &&
			      fvdat->flag & FN_SIZECHANGE) ||
			     ((vap = VTOVA(vp)) &&
			      filesize != vap->va_size)))
			{
				fvdat->flag &= ~FN_SIZECHANGE;
				/*
				 * The server changed the file's size even
				 * though we had it cached, or had dirty writes
				 * in the WB cache!
				 */
				fuse_warn(data, FSESS_WARN_CACHE_INCOHERENT,
				    "cache incoherent!  "
				    "To prevent "
				    "data corruption, disable the data cache "
				    "by mounting with -o direct_io, or as "
				    "directed otherwise by your FUSE server's "
				    "documentation.");
				int iosize = fuse_iosize(vp);
				v_inval_buf_range(vp, 0, INT64_MAX, iosize);
			}

			MPASS(feo != NULL);
			fuse_internal_cache_attrs(*vpp, &feo->attr,
				feo->attr_valid, feo->attr_valid_nsec, NULL, true);
			fuse_validity_2_bintime(feo->entry_valid,
				feo->entry_valid_nsec,
				&fvdat->entry_cache_timeout);

Lines 75-80 void expect_lookup(const char *relpath, uint64_t ino, off_t size) Link Here

(-)b/tests/sys/fs/fusefs/bmap.cc (+86 lines)
75	}	75	}
76	};	76	};
77		77
		78	class BmapEof: public Bmap, public WithParamInterface<int> {};
		79
78	/*	80	/*
79	* Test FUSE_BMAP	81	* Test FUSE_BMAP
80	* XXX The FUSE protocol does not include the runp and runb variables, so those	82	* XXX The FUSE protocol does not include the runp and runb variables, so those
Lines 165-167 TEST_F(Bmap, default_) Link Here
165		167
166	leak(fd);	168	leak(fd);
167	}	169	}
		170
		171	/*
		172	* VOP_BMAP should not query the server for the file's size, even if its cached
		173	* attributes have expired.
		174	* Regression test for https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=256937
		175	*/
		176	TEST_P(BmapEof, eof)
		177	{
		178	/*
		179	* Outline:
		180	* 1) lookup the file, setting attr_valid=0
		181	* 2) Read more than one block, causing the kernel to issue VOP_BMAP to
		182	* plan readahead.
		183	* 3) Nothing should panic
		184	* 4) Repeat the tests, truncating the file after different numbers of
		185	* GETATTR operations.
		186	*/
		187	Sequence seq;
		188	const off_t filesize = 2 * m_maxbcachebuf;
		189	const ino_t ino = 42;
		190	mode_t mode = S_IFREG \| 0644;
		191	void contents, buf;
		192	int fd;
		193	int ngetattrs;
		194
		195	ngetattrs = GetParam();
		196	contents = calloc(1, filesize);
		197	FuseTest::expect_lookup(RELPATH, ino, mode, filesize, 1, 0);
		198	expect_open(ino, 0, 1);
		199	// Depending on ngetattrs, FUSE_READ could be called with either
		200	// filesize or filesize / 2 .
		201	EXPECT_CALL(*m_mock, process(
		202	ResultOf([=](auto in) {
		203	return (in.header.opcode == FUSE_READ &&
		204	in.header.nodeid == ino &&
		205	in.body.read.offset == 0 &&
		206	( in.body.read.size == filesize \|\|
		207	in.body.read.size == filesize / 2));
		208	}, Eq(true)),
		209	_)
		210	).WillOnce(Invoke(ReturnImmediate([=](auto in, auto& out) {
		211	size_t osize = in.body.read.size;
		212	out.header.len = sizeof(struct fuse_out_header) + osize;
		213	bzero(out.body.bytes, osize);
		214	})));
		215	EXPECT_CALL(*m_mock, process(
		216	ResultOf([](auto in) {
		217	return (in.header.opcode == FUSE_GETATTR &&
		218	in.header.nodeid == ino);
		219	}, Eq(true)),
		220	_)
		221	).Times(Between(ngetattrs - 1, ngetattrs))
		222	.InSequence(seq)
		223	.WillRepeatedly(Invoke(ReturnImmediate([=](auto i __unused, auto& out) {
		224	SET_OUT_HEADER_LEN(out, attr);
		225	out.body.attr.attr_valid = 0;
		226	out.body.attr.attr.ino = ino;
		227	out.body.attr.attr.mode = S_IFREG \| 0644;
		228	out.body.attr.attr.size = filesize;
		229	})));
		230	EXPECT_CALL(*m_mock, process(
		231	ResultOf([](auto in) {
		232	return (in.header.opcode == FUSE_GETATTR &&
		233	in.header.nodeid == ino);
234	}, Eq(true)),
235	_)
236	).InSequence(seq)
237	.WillRepeatedly(Invoke(ReturnImmediate([=](auto i __unused, auto& out) {
238	SET_OUT_HEADER_LEN(out, attr);
239	out.body.attr.attr_valid = 0;
240	out.body.attr.attr.ino = ino;
241	out.body.attr.attr.mode = S_IFREG \| 0644;
242	out.body.attr.attr.size = filesize / 2;
243	})));
244
245	buf = calloc(1, filesize);
246	fd = open(FULLPATH, O_RDWR);
247	ASSERT_LE(0, fd) << strerror(errno);
248	read(fd, buf, filesize);
249	}
250
251	INSTANTIATE_TEST_CASE_P(BE, BmapEof,
252	Values(1, 2, 3)
253	);

Lines 208-213 virtual void SetUp() { Link Here

(-)b/tests/sys/fs/fusefs/write.cc (+81 lines)
208	}	208	}
209	};	209	};
210		210
		211	class WriteEofDuringVnopStrategy: public Write, public WithParamInterface<int>
		212	{};
		213
211	void sigxfsz_handler(int __unused sig) {	214	void sigxfsz_handler(int __unused sig) {
212	Write::s_sigxfsz = 1;	215	Write::s_sigxfsz = 1;
213	}	216	}
Lines 526-531 TEST_F(Write, eof_during_rmw) Link Here
526	leak(fd);	529	leak(fd);
527	}	530	}
528		531
		532	/*
		533	* VOP_STRATEGY should not query the server for the file's size, even if its
		534	* cached attributes have expired.
		535	* Regression test for https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=256937
		536	*/
		537	TEST_P(WriteEofDuringVnopStrategy, eof_during_vop_strategy)
		538	{
		539	const char FULLPATH[] = "mountpoint/some_file.txt";
		540	const char RELPATH[] = "some_file.txt";
		541	Sequence seq;
		542	const off_t filesize = 2 * m_maxbcachebuf;
		543	void *contents;
		544	uint64_t ino = 42;
		545	uint64_t attr_valid = 0;
		546	uint64_t attr_valid_nsec = 0;
		547	mode_t mode = S_IFREG \| 0644;
		548	int fd;
		549	int ngetattrs;
		550
		551	ngetattrs = GetParam();
		552	contents = calloc(1, filesize);
		553
		554	EXPECT_LOOKUP(FUSE_ROOT_ID, RELPATH)
		555	.WillRepeatedly(Invoke(
		556	ReturnImmediate([=](auto in __unused, auto& out) {
		557	SET_OUT_HEADER_LEN(out, entry);
		558	out.body.entry.attr.mode = mode;
		559	out.body.entry.nodeid = ino;
		560	out.body.entry.attr.nlink = 1;
		561	out.body.entry.attr.size = filesize;
		562	out.body.entry.attr_valid = attr_valid;
		563	out.body.entry.attr_valid_nsec = attr_valid_nsec;
		564	})));
		565	expect_open(ino, 0, 1);
		566	EXPECT_CALL(*m_mock, process(
		567	ResultOf([=](auto in) {
		568	return (in.header.opcode == FUSE_GETATTR &&
		569	in.header.nodeid == ino);
		570	}, Eq(true)),
		571	_)
		572	).Times(Between(ngetattrs - 1, ngetattrs))
		573	.InSequence(seq)
		574	.WillRepeatedly(Invoke(ReturnImmediate([=](auto i __unused, auto& out) {
		575	SET_OUT_HEADER_LEN(out, attr);
		576	out.body.attr.attr.ino = ino;
		577	out.body.attr.attr.mode = mode;
		578	out.body.attr.attr_valid = attr_valid;
		579	out.body.attr.attr_valid_nsec = attr_valid_nsec;
		580	out.body.attr.attr.size = filesize;
		581	})));
		582	EXPECT_CALL(*m_mock, process(
		583	ResultOf([=](auto in) {
		584	return (in.header.opcode == FUSE_GETATTR &&
		585	in.header.nodeid == ino);
		586	}, Eq(true)),
		587	_)
		588	).InSequence(seq)
		589	.WillRepeatedly(Invoke(ReturnImmediate([=](auto i __unused, auto& out) {
		590	SET_OUT_HEADER_LEN(out, attr);
		591	out.body.attr.attr.ino = ino;
		592	out.body.attr.attr.mode = mode;
		593	out.body.attr.attr_valid = attr_valid;
		594	out.body.attr.attr_valid_nsec = attr_valid_nsec;
		595	out.body.attr.attr.size = filesize / 2;
596	})));
597	expect_write(ino, 0, filesize / 2, filesize / 2, contents);
598
599	fd = open(FULLPATH, O_RDWR);
600	ASSERT_LE(0, fd) << strerror(errno);
601	ASSERT_EQ(filesize / 2, write(fd, contents, filesize / 2))
602	<< strerror(errno);
603
604	}
605
606	INSTANTIATE_TEST_CASE_P(W, WriteEofDuringVnopStrategy,
607	Values(1, 2, 3)
608	);
609
529	/*	610	/*
530	* If the kernel cannot be sure which uid, gid, or pid was responsible for a	611	* If the kernel cannot be sure which uid, gid, or pid was responsible for a
531	* write, then it must set the FUSE_WRITE_CACHE bit	612	* write, then it must set the FUSE_WRITE_CACHE bit

Return to bug 256937

Lines 255-261 fuse_internal_access(struct vnode *vp, Link Here

(-)b/sys/fs/fuse/fuse_internal.c (-23 / +51 lines)
255	*/	255	*/
256	void	256	void
257	fuse_internal_cache_attrs(struct vnode vp, struct fuse_attr attr,	257	fuse_internal_cache_attrs(struct vnode vp, struct fuse_attr attr,
258	uint64_t attr_valid, uint32_t attr_valid_nsec, struct vattr *vap)	258	uint64_t attr_valid, uint32_t attr_valid_nsec, struct vattr *vap,
		259	bool from_server)
259	{	260	{
260	struct mount *mp;	261	struct mount *mp;
261	struct fuse_vnode_data *fvdat;	262	struct fuse_vnode_data *fvdat;
Lines 271-279 fuse_internal_cache_attrs(struct vnode vp, struct fuse_attr attr, Link Here
271	fuse_validity_2_bintime(attr_valid, attr_valid_nsec,	272	fuse_validity_2_bintime(attr_valid, attr_valid_nsec,
272	&fvdat->attr_cache_timeout);	273	&fvdat->attr_cache_timeout);
273		274
		275	if (vnode_isreg(vp) &&
		276	fvdat->cached_attrs.va_size != VNOVAL &&
		277	attr->size != fvdat->cached_attrs.va_size)
		278	{
		279	if ( data->cache_mode == FUSE_CACHE_WB &&
		280	fvdat->flag & FN_SIZECHANGE)
		281	{
		282	const char *msg;
		283
		284	/*
		285	* The server changed the file's size even though we're
		286	* using writeback cacheing and and we have outstanding
		287	* dirty writes! That's a server bug.
		288	*/
		289	if (fuse_libabi_geq(data, 7, 23)) {
		290	msg = "writeback cache incoherent!."
		291	"To prevent data corruption, disable "
		292	"the writeback cache according to your "
		293	"FUSE server's documentation.";
		294	} else {
		295	msg = "writeback cache incoherent!."
		296	"To prevent data corruption, disable "
		297	"the writeback cache by setting "
		298	"vfs.fusefs.data_cache_mode to 0 or 1.";
		299	}
		300	fuse_warn(data, FSESS_WARN_WB_CACHE_INCOHERENT, msg);
		301	}
		302	if (fuse_vnode_attr_cache_valid(vp) &&
		303	data->cache_mode != FUSE_CACHE_UC)
		304	{
		305	/*
		306	* The server changed the file's size even though we
		307	* have it cached and our cache has not yet expired.
		308	* That's a bug.
		309	*/
		310	fuse_warn(data, FSESS_WARN_CACHE_INCOHERENT,
		311	"cache incoherent! "
		312	"To prevent "
		313	"data corruption, disable the data cache "
		314	"by mounting with -o direct_io, or as "
		315	"directed otherwise by your FUSE server's "
		316	"documentation.");
		317	}
		318	}
		319
274	/* Fix our buffers if the filesize changed without us knowing */	320	/* Fix our buffers if the filesize changed without us knowing */
275	if (vnode_isreg(vp) && attr->size != fvdat->cached_attrs.va_size) {	321	if (vnode_isreg(vp) && attr->size != fvdat->cached_attrs.va_size) {
276	(void)fuse_vnode_setsize(vp, attr->size);	322	(void)fuse_vnode_setsize(vp, attr->size, from_server);
277	fvdat->cached_attrs.va_size = attr->size;	323	fvdat->cached_attrs.va_size = attr->size;
278	}	324	}
279		325
Lines 806-812 fuse_internal_newentry_core(struct vnode *dvp, Link Here
806	fuse_vnode_clear_attr_cache(dvp);	852	fuse_vnode_clear_attr_cache(dvp);
807		853
808	fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,	854	fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,
809	feo->attr_valid_nsec, NULL);	855	feo->attr_valid_nsec, NULL, true);
810		856
811	return err;	857	return err;
812	}	858	}
Lines 912-937 fuse_internal_do_getattr(struct vnode vp, struct vattr vap, Link Here
912	fao->attr.mtime = old_mtime.tv_sec;	958	fao->attr.mtime = old_mtime.tv_sec;
913	fao->attr.mtimensec = old_mtime.tv_nsec;	959	fao->attr.mtimensec = old_mtime.tv_nsec;
914	}	960	}
915	if (vnode_isreg(vp) &&
916	fvdat->cached_attrs.va_size != VNOVAL &&
917	fao->attr.size != fvdat->cached_attrs.va_size) {
918	/*
919	* The server changed the file's size even though we had it
920	* cached! That's a server bug.
921	*/
922	struct mount *mp = vnode_mount(vp);
923	struct fuse_data *data = fuse_get_mpdata(mp);
924
925	fuse_warn(data, FSESS_WARN_CACHE_INCOHERENT,
926	"cache incoherent! "
927	"To prevent data corruption, disable the data cache "
928	"by mounting with -o direct_io, or as directed "
929	"otherwise by your FUSE server's documentation.");
930	int iosize = fuse_iosize(vp);
931	v_inval_buf_range(vp, 0, INT64_MAX, iosize);
932	}
933	fuse_internal_cache_attrs(vp, &fao->attr, fao->attr_valid,	961	fuse_internal_cache_attrs(vp, &fao->attr, fao->attr_valid,
934	fao->attr_valid_nsec, vap);	962	fao->attr_valid_nsec, vap, true);
935	if (vtyp != vnode_vtype(vp)) {	963	if (vtyp != vnode_vtype(vp)) {
936	fuse_internal_vnode_disappear(vp);	964	fuse_internal_vnode_disappear(vp);
937	err = ENOENT;	965	err = ENOENT;
Lines 1231-1237 int fuse_internal_setattr(struct vnode vp, struct vattr vap, Link Here
1231	struct fuse_attr_out fao = (struct fuse_attr_out)fdi.answ;	1259	struct fuse_attr_out fao = (struct fuse_attr_out)fdi.answ;
1232	fuse_vnode_undirty_cached_timestamps(vp);	1260	fuse_vnode_undirty_cached_timestamps(vp);
1233	fuse_internal_cache_attrs(vp, &fao->attr, fao->attr_valid,	1261	fuse_internal_cache_attrs(vp, &fao->attr, fao->attr_valid,
1234	fao->attr_valid_nsec, NULL);	1262	fao->attr_valid_nsec, NULL, false);
1235	}	1263	}
1236		1264
1237	out:	1265	out:

Lines 571-577 fuse_write_directbackend(struct vnode vp, struct uio uio, Link Here

(-)b/sys/fs/fuse/fuse_io.c (-9 / +14 lines)
571	as_written_offset = uio->uio_offset - diff;	571	as_written_offset = uio->uio_offset - diff;
572		572
573	if (as_written_offset - diff > filesize)	573	if (as_written_offset - diff > filesize)
574	fuse_vnode_setsize(vp, as_written_offset);	574	fuse_vnode_setsize(vp, as_written_offset, false);
575	if (as_written_offset - diff >= filesize)	575	if (as_written_offset - diff >= filesize)
576	fvdat->flag &= ~FN_SIZECHANGE;	576	fvdat->flag &= ~FN_SIZECHANGE;
577		577
Lines 715-721 fuse_write_biobackend(struct vnode vp, struct uio uio, Link Here
715	* Extend file _after_ locking buffer so we won't race	715	* Extend file _after_ locking buffer so we won't race
716	* with other readers	716	* with other readers
717	*/	717	*/
718	err = fuse_vnode_setsize(vp, uio->uio_offset + n);	718	err = fuse_vnode_setsize(vp, uio->uio_offset + n, false);
719	filesize = uio->uio_offset + n;	719	filesize = uio->uio_offset + n;
720	fvdat->flag \|= FN_SIZECHANGE;	720	fvdat->flag \|= FN_SIZECHANGE;
721	if (err) {	721	if (err) {
Lines 1007-1019 fuse_io_strategy(struct vnode vp, struct buf bp) Link Here
1007	/*	1007	/*
1008	* Setup for actual write	1008	* Setup for actual write
1009	*/	1009	*/
1010	error = fuse_vnode_size(vp, &filesize, cred, curthread);	1010	/*
1011	if (error) {	1011	* If the file's size is cached, use that value, even if the
1012	bp->b_ioflags \|= BIO_ERROR;	1012	* cache is expired. At this point we're already committed to
1013	bp->b_error = error;	1013	* writing something. If the FUSE server has changed the
1014	bufdone(bp);	1014	* file's size behind our back, it's too late for us to do
1015	return (error);	1015	* anything about it. In particular, we can't invalidate any
1016	}	1016	* part of the file's buffers because VOP_STRATEGY is called
		1017	* with them already locked.
		1018	*/
		1019	filesize = fvdat->cached_attrs.va_size;
		1020	/* filesize must've been cached by fuse_vnop_open. */
		1021	KASSERT(filesize != VNOVAL, ("filesize should've been cached"));
1017		1022
1018	if ((off_t)bp->b_lblkno * biosize + bp->b_dirtyend > filesize)	1023	if ((off_t)bp->b_lblkno * biosize + bp->b_dirtyend > filesize)
1019	bp->b_dirtyend = filesize -	1024	bp->b_dirtyend = filesize -

Lines 539-545 fuse_vfsop_vget(struct mount mp, ino_t ino, int flags, struct vnode *vpp) Link Here

(-)b/sys/fs/fuse/fuse_vfsops.c (-39 / +1 lines)
539	struct fuse_entry_out *feo;	539	struct fuse_entry_out *feo;
540	struct fuse_vnode_data *fvdat;	540	struct fuse_vnode_data *fvdat;
541	const char dot[] = ".";	541	const char dot[] = ".";
542	off_t filesize;
543	enum vtype vtyp;	542	enum vtype vtyp;
544	int error;	543	int error;
545		544
Lines 576-622 fuse_vfsop_vget(struct mount mp, ino_t ino, int flags, struct vnode *vpp) Link Here
576	error = fuse_vnode_get(mp, feo, nodeid, NULL, vpp, NULL, vtyp);	575	error = fuse_vnode_get(mp, feo, nodeid, NULL, vpp, NULL, vtyp);
577	if (error)	576	if (error)
578	goto out;	577	goto out;
579	filesize = feo->attr.size;
580
581	/*
582	* In the case where we are looking up a FUSE node represented by an
583	* existing cached vnode, and the true size reported by FUSE_LOOKUP
584	* doesn't match the vnode's cached size, then any cached writes beyond
585	* the file's current size are lost.
586	*
587	* We can get here:
588	* * following attribute cache expiration, or
589	* * due a bug in the daemon, or
590	*/
591	fvdat = VTOFUD(*vpp);	578	fvdat = VTOFUD(*vpp);
592	if (vnode_isreg(*vpp) &&
593	filesize != fvdat->cached_attrs.va_size &&
594	fvdat->flag & FN_SIZECHANGE) {
595	if (data->cache_mode == fuse_data_cache_mode) {
596	const char *msg;
597
598	if (fuse_libabi_geq(data, 7, 23)) {
599	msg = "writeback cache incoherent!."
600	"To prevent data corruption, disable "
601	"the writeback cache according to your "
602	"FUSE server's documentation.";
603	} else {
604	msg = "writeback cache incoherent!."
605	"To prevent data corruption, disable "
606	"the writeback cache by setting "
607	"vfs.fusefs.data_cache_mode to 0 or 1.";
608	}
609	fuse_warn(data, FSESS_WARN_WB_CACHE_INCOHERENT, msg);
610	} else {
611	/* If we get here, it's likely a fusefs kernel bug */
612	printf("%s: WB cache incoherent on %s!\n", __func__,
613	vnode_mount(*vpp)->mnt_stat.f_mntonname);
614	}
615	fvdat->flag &= ~FN_SIZECHANGE;
616	}
617		579
618	fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,	580	fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,
619	feo->attr_valid_nsec, NULL);	581	feo->attr_valid_nsec, NULL, true);
620	fuse_validity_2_bintime(feo->entry_valid, feo->entry_valid_nsec,	582	fuse_validity_2_bintime(feo->entry_valid, feo->entry_valid_nsec,
621	&fvdat->entry_cache_timeout);	583	&fvdat->entry_cache_timeout);
622	out:	584	out:

Lines 516-523 fuse_vnop_bmap(struct vop_bmap_args *ap) Link Here

(-)b/sys/fs/fuse/fuse_vnops.c (-42 / +19 lines)
516	struct fuse_bmap_in *fbi;	516	struct fuse_bmap_in *fbi;
517	struct fuse_bmap_out *fbo;	517	struct fuse_bmap_out *fbo;
518	struct fuse_data *data;	518	struct fuse_data *data;
		519	struct fuse_vnode_data *fvdat = VTOFUD(vp);
519	uint64_t biosize;	520	uint64_t biosize;
520	off_t filesize;	521	off_t fsize;
521	daddr_t lbn = ap->a_bn;	522	daddr_t lbn = ap->a_bn;
522	daddr_t *pbn = ap->a_bnp;	523	daddr_t *pbn = ap->a_bnp;
523	int *runp = ap->a_runp;	524	int *runp = ap->a_runp;
Lines 550-559 fuse_vnop_bmap(struct vop_bmap_args *ap) Link Here
550	*/	551	*/
551	if (runb != NULL)	552	if (runb != NULL)
552	*runb = MIN(lbn, maxrun);	553	*runb = MIN(lbn, maxrun);
553	if (runp != NULL) {	554	if (runp != NULL && maxrun == 0)
554	error = fuse_vnode_size(vp, &filesize, td->td_ucred, td);	555	*runp = 0;
		556	else if (runp != NULL) {
		557	/*
		558	* If the file's size is cached, use that value to calculate
		559	* runp, even if the cache is expired. runp is only advisory,
		560	* and the risk of getting it wrong is not worth the cost of
		561	* another upcall.
		562	*/
		563	if (fvdat->cached_attrs.va_size != VNOVAL)
		564	fsize = fvdat->cached_attrs.va_size;
		565	else
		566	error = fuse_vnode_size(vp, &fsize, td->td_ucred, td);
555	if (error == 0)	567	if (error == 0)
556	*runp = MIN(MAX(0, filesize / (off_t)biosize - lbn - 1),	568	*runp = MIN(MAX(0, fsize / (off_t)biosize - lbn - 1),
557	maxrun);	569	maxrun);
558	else	570	else
559	*runp = 0;	571	*runp = 0;
Lines 895-901 fuse_vnop_create(struct vop_create_args *ap) Link Here
895	}	907	}
896	ASSERT_VOP_ELOCKED(*vpp, "fuse_vnop_create");	908	ASSERT_VOP_ELOCKED(*vpp, "fuse_vnop_create");
897	fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,	909	fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,
898	feo->attr_valid_nsec, NULL);	910	feo->attr_valid_nsec, NULL, true);
899		911
900	fuse_filehandle_init(*vpp, FUFH_RDWR, NULL, td, cred, foo);	912	fuse_filehandle_init(*vpp, FUFH_RDWR, NULL, td, cred, foo);
901	fuse_vnode_open(*vpp, foo->open_flags, td);	913	fuse_vnode_open(*vpp, foo->open_flags, td);
Lines 1151-1157 fuse_vnop_link(struct vop_link_args *ap) Link Here
1151	*/	1163	*/
1152	fuse_vnode_clear_attr_cache(tdvp);	1164	fuse_vnode_clear_attr_cache(tdvp);
1153	fuse_internal_cache_attrs(vp, &feo->attr, feo->attr_valid,	1165	fuse_internal_cache_attrs(vp, &feo->attr, feo->attr_valid,
1154	feo->attr_valid_nsec, NULL);	1166	feo->attr_valid_nsec, NULL, true);
1155	}	1167	}
1156	out:	1168	out:
1157	fdisp_destroy(&fdi);	1169	fdisp_destroy(&fdi);
Lines 1360-1411 fuse_vnop_lookup(struct vop_lookup_args *ap) Link Here
1360	*vpp = dvp;	1372	*vpp = dvp;
1361	} else {	1373	} else {
1362	struct fuse_vnode_data *fvdat;	1374	struct fuse_vnode_data *fvdat;
1363	struct vattr *vap;
1364		1375
1365	err = fuse_vnode_get(vnode_mount(dvp), feo, nid, dvp,	1376	err = fuse_vnode_get(vnode_mount(dvp), feo, nid, dvp,
1366	&vp, cnp, vtyp);	1377	&vp, cnp, vtyp);
1367	if (err)	1378	if (err)
1368	goto out;	1379	goto out;
1369	*vpp = vp;	1380	*vpp = vp;
1370
1371	/*
1372	* In the case where we are looking up a FUSE node
1373	* represented by an existing cached vnode, and the
1374	* true size reported by FUSE_LOOKUP doesn't match
1375	* the vnode's cached size, then any cached writes
1376	* beyond the file's current size are lost.
1377	*
1378	* We can get here:
1379	* * following attribute cache expiration, or
1380	* * due a bug in the daemon, or
1381	*/
1382	fvdat = VTOFUD(vp);	1381	fvdat = VTOFUD(vp);
1383	if (vnode_isreg(vp) &&
1384	((filesize != fvdat->cached_attrs.va_size &&
1385	fvdat->flag & FN_SIZECHANGE) \|\|
1386	((vap = VTOVA(vp)) &&
1387	filesize != vap->va_size)))
1388	{
1389	fvdat->flag &= ~FN_SIZECHANGE;
1390	/*
1391	* The server changed the file's size even
1392	* though we had it cached, or had dirty writes
1393	* in the WB cache!
1394	*/
1395	fuse_warn(data, FSESS_WARN_CACHE_INCOHERENT,
1396	"cache incoherent! "
1397	"To prevent "
1398	"data corruption, disable the data cache "
1399	"by mounting with -o direct_io, or as "
1400	"directed otherwise by your FUSE server's "
1401	"documentation.");
1402	int iosize = fuse_iosize(vp);
1403	v_inval_buf_range(vp, 0, INT64_MAX, iosize);
1404	}
1405		1382
1406	MPASS(feo != NULL);	1383	MPASS(feo != NULL);
1407	fuse_internal_cache_attrs(*vpp, &feo->attr,	1384	fuse_internal_cache_attrs(*vpp, &feo->attr,
1408	feo->attr_valid, feo->attr_valid_nsec, NULL);	1385	feo->attr_valid, feo->attr_valid_nsec, NULL, true);
1409	fuse_validity_2_bintime(feo->entry_valid,	1386	fuse_validity_2_bintime(feo->entry_valid,
1410	feo->entry_valid_nsec,	1387	feo->entry_valid_nsec,
1411	&fvdat->entry_cache_timeout);	1388	&fvdat->entry_cache_timeout);